Theorem ontric3g 43973

Description: For all 𝑥, 𝑦 ∈ On, one and only one of the following hold: 𝑥 ∈ 𝑦, 𝑦 = 𝑥, or 𝑦 ∈ 𝑥. This is a transparent strict trichotomy. (Contributed by RP, 27-Sep-2023.)

Assertion

Ref	Expression
ontric3g	⊢ ∀𝑥 ∈ On ∀𝑦 ∈ On ((𝑥 ∈ 𝑦 ↔ ¬ (𝑦 = 𝑥 ∨ 𝑦 ∈ 𝑥)) ∧ (𝑦 = 𝑥 ↔ ¬ (𝑥 ∈ 𝑦 ∨ 𝑦 ∈ 𝑥)) ∧ (𝑦 ∈ 𝑥 ↔ ¬ (𝑥 ∈ 𝑦 ∨ 𝑦 = 𝑥)))

Distinct variable group:   𝑥,𝑦

Proof of Theorem ontric3g

Step	Hyp	Ref	Expression
1		orcom 876	. . . . . . 7 ⊢ ((𝑦 = 𝑥 ∨ 𝑦 ∈ 𝑥) ↔ (𝑦 ∈ 𝑥 ∨ 𝑦 = 𝑥))
2	1	a1i 11	. . . . . 6 ⊢ ((𝑦 ∈ On ∧ 𝑥 ∈ On) → ((𝑦 = 𝑥 ∨ 𝑦 ∈ 𝑥) ↔ (𝑦 ∈ 𝑥 ∨ 𝑦 = 𝑥)))
3		onsseleq 6358	. . . . . 6 ⊢ ((𝑦 ∈ On ∧ 𝑥 ∈ On) → (𝑦 ⊆ 𝑥 ↔ (𝑦 ∈ 𝑥 ∨ 𝑦 = 𝑥)))
4		ontri1 6351	. . . . . 6 ⊢ ((𝑦 ∈ On ∧ 𝑥 ∈ On) → (𝑦 ⊆ 𝑥 ↔ ¬ 𝑥 ∈ 𝑦))
5	2, 3, 4	3bitr2d 308	. . . . 5 ⊢ ((𝑦 ∈ On ∧ 𝑥 ∈ On) → ((𝑦 = 𝑥 ∨ 𝑦 ∈ 𝑥) ↔ ¬ 𝑥 ∈ 𝑦))
6	5	con2bid 355	. . . 4 ⊢ ((𝑦 ∈ On ∧ 𝑥 ∈ On) → (𝑥 ∈ 𝑦 ↔ ¬ (𝑦 = 𝑥 ∨ 𝑦 ∈ 𝑥)))
7	6	ancoms 459	. . 3 ⊢ ((𝑥 ∈ On ∧ 𝑦 ∈ On) → (𝑥 ∈ 𝑦 ↔ ¬ (𝑦 = 𝑥 ∨ 𝑦 ∈ 𝑥)))
8	4	ancoms 459	. . . . 5 ⊢ ((𝑥 ∈ On ∧ 𝑦 ∈ On) → (𝑦 ⊆ 𝑥 ↔ ¬ 𝑥 ∈ 𝑦))
9		ontri1 6351	. . . . 5 ⊢ ((𝑥 ∈ On ∧ 𝑦 ∈ On) → (𝑥 ⊆ 𝑦 ↔ ¬ 𝑦 ∈ 𝑥))
10	8, 9	anbi12d 638	. . . 4 ⊢ ((𝑥 ∈ On ∧ 𝑦 ∈ On) → ((𝑦 ⊆ 𝑥 ∧ 𝑥 ⊆ 𝑦) ↔ (¬ 𝑥 ∈ 𝑦 ∧ ¬ 𝑦 ∈ 𝑥)))
11		eqss 3937	. . . 4 ⊢ (𝑦 = 𝑥 ↔ (𝑦 ⊆ 𝑥 ∧ 𝑥 ⊆ 𝑦))
12		ioran 991	. . . 4 ⊢ (¬ (𝑥 ∈ 𝑦 ∨ 𝑦 ∈ 𝑥) ↔ (¬ 𝑥 ∈ 𝑦 ∧ ¬ 𝑦 ∈ 𝑥))
13	10, 11, 12	3bitr4g 315	. . 3 ⊢ ((𝑥 ∈ On ∧ 𝑦 ∈ On) → (𝑦 = 𝑥 ↔ ¬ (𝑥 ∈ 𝑦 ∨ 𝑦 ∈ 𝑥)))
14		equcom 2025	. . . . . . 7 ⊢ (𝑦 = 𝑥 ↔ 𝑥 = 𝑦)
15	14	orbi2i 918	. . . . . 6 ⊢ ((𝑥 ∈ 𝑦 ∨ 𝑦 = 𝑥) ↔ (𝑥 ∈ 𝑦 ∨ 𝑥 = 𝑦))
16	15	a1i 11	. . . . 5 ⊢ ((𝑥 ∈ On ∧ 𝑦 ∈ On) → ((𝑥 ∈ 𝑦 ∨ 𝑦 = 𝑥) ↔ (𝑥 ∈ 𝑦 ∨ 𝑥 = 𝑦)))
17		onsseleq 6358	. . . . 5 ⊢ ((𝑥 ∈ On ∧ 𝑦 ∈ On) → (𝑥 ⊆ 𝑦 ↔ (𝑥 ∈ 𝑦 ∨ 𝑥 = 𝑦)))
18	16, 17, 9	3bitr2d 308	. . . 4 ⊢ ((𝑥 ∈ On ∧ 𝑦 ∈ On) → ((𝑥 ∈ 𝑦 ∨ 𝑦 = 𝑥) ↔ ¬ 𝑦 ∈ 𝑥))
19	18	con2bid 355	. . 3 ⊢ ((𝑥 ∈ On ∧ 𝑦 ∈ On) → (𝑦 ∈ 𝑥 ↔ ¬ (𝑥 ∈ 𝑦 ∨ 𝑦 = 𝑥)))
20	7, 13, 19	3jca 1134	. 2 ⊢ ((𝑥 ∈ On ∧ 𝑦 ∈ On) → ((𝑥 ∈ 𝑦 ↔ ¬ (𝑦 = 𝑥 ∨ 𝑦 ∈ 𝑥)) ∧ (𝑦 = 𝑥 ↔ ¬ (𝑥 ∈ 𝑦 ∨ 𝑦 ∈ 𝑥)) ∧ (𝑦 ∈ 𝑥 ↔ ¬ (𝑥 ∈ 𝑦 ∨ 𝑦 = 𝑥))))
21	20	rgen2 3180	1 ⊢ ∀𝑥 ∈ On ∀𝑦 ∈ On ((𝑥 ∈ 𝑦 ↔ ¬ (𝑦 = 𝑥 ∨ 𝑦 ∈ 𝑥)) ∧ (𝑦 = 𝑥 ↔ ¬ (𝑥 ∈ 𝑦 ∨ 𝑦 ∈ 𝑥)) ∧ (𝑦 ∈ 𝑥 ↔ ¬ (𝑥 ∈ 𝑦 ∨ 𝑦 = 𝑥)))

Syntax hints:  ¬ wn 3   ↔ wb 207   ∧ wa 396   ∨ wo 853   ∧ w3a 1092   ∈ wcel 2119  ∀wral 3054   ⊆ wss 3890  Oncon0 6317

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1802  ax-4 1816  ax-5 1917  ax-6 1974  ax-7 2015  ax-8 2121  ax-9 2129  ax-ext 2712  ax-sep 5225  ax-pr 5369

This theorem depends on definitions:  df-bi 208  df-an 397  df-or 854  df-3or 1093  df-3an 1094  df-tru 1550  df-fal 1560  df-ex 1787  df-sb 2074  df-clab 2719  df-cleq 2732  df-clel 2815  df-ne 2936  df-ral 3055  df-rex 3065  df-rab 3393  df-v 3434  df-dif 3893  df-un 3895  df-in 3897  df-ss 3907  df-pss 3910  df-nul 4269  df-if 4462  df-pw 4538  df-sn 4563  df-pr 4565  df-op 4569  df-uni 4846  df-br 5080  df-opab 5142  df-tr 5187  df-eprel 5525  df-po 5533  df-so 5534  df-fr 5578  df-we 5580  df-ord 6320  df-on 6321

This theorem is referenced by: (None)